An X-ray CT apparatus, which includes an X-ray source which irradiates an object with X-rays and an X-ray detector which detects a dose of X-rays transmitted through the object as projection data, reconstructs a tomographic image of the object by using pieces of projection data from a plurality of angles obtained by rotating the X-ray source and the X-ray detector around the object, and displays the reconstructed tomographic image. An image displayed by the X-ray CT apparatus draws a shape of an organ of an object, and is used for image diagnosis.
Various conditions such as a range of a tomographic image of an object to be obtained, and a method of obtaining projection data by rotating a rotation disk at a predetermined speed under a predetermined X-ray condition, are set on an operation console in advance, the X-ray CT apparatus transitions to a state in which scanning can be started on the basis of the conditions, then controls a scan gantry in a scan room so as to obtain a tomographic image, and displays the tomographic image.
In examination using an X-ray CT apparatus, as a method for increasing the number of examinations, there is a method in which two operators respectively located at an operation console and in a scan room perform examination. In this use method, particularly, in contrast scanning examination requiring the care of an object (securing of a contrast agent injection route), there are many cases where the X-ray CT apparatus starts scanning while checking a situation of a contrast agent injection route in the object, and thus it is useful that there is means for bringing the X-ray CT apparatus into a state in which scanning can be performed from the scan room.
For example, PTL 1 discloses a method in which an operation console which plans scanning conditions and a scanning range and a scan room which takes care of an object independently generate signals at the time when preparation is completed, and transition to a state in which scanning can be started at the time when both of the signals are provided.